1. Field of the Invention
This invention relates to equipment used in construction. Specifically, this invention relates to an accessory for a platform used for lifting workers and materials to an elevated position.
2. Description of the Background
During construction of buildings and other structures, it is often necessary to lift workers and materials to elevated levels. Lifting platforms are known in the prior art. Aerial work platform assemblies are well known devices for lifting workers or equipment to elevated work areas. In construction applications, these lifting platforms have been lifted by ground-based vehicles such as forklifts or scissor lifts.
Aerial platforms are shown, for instance, in U.S. Pat. Nos. 7,182,173 and 5,683,063. As shown, the platform includes a boom/lift and a work stand. One end of the boom is usually mounted to a vehicle or mobile chassis. The other end of the boom/lift is attached to the work stand. Typically, a controller raises the end of the boom/lift that is attached to the work stand to a desired aerial work site. The work stand includes a floor, spaced vertical bars, and horizontal rails on the top end of the vertical bars.
In some instances, the aerial work apparatus will have a material-handling device such as a winch or forklift with which to lift tools and supplies to and from an elevated work site attached at the outer end of the boom/lift. Since the choice of device attached to the boom/lift is usually permanent and not exchangeable, a separate apparatus is therefore needed for each type of lifting operation. In particular, while one aerial lift may be needed to raise material to an elevated work site, a different lift will be required to provide a working platform for those individuals needed to complete the job.
Although a certain amount of material can be carried with the workers in their aerial platform, space and safety considerations limit, in most instances, the number and size of such items. Moreover, there has been an understandable tendency to avoid placing personnel in the air with a heavy load.
To attach equipment to the work stand, poles or tubes may be secured to the vertical bars or horizontal rails with rope, vice grip chain clamps, and the like. Numerous other apparatus and equipment have also been attached to the work stand or aerial work platforms in a similar fashion using rope or vice grip chain clamps.
However, the use of rope to tie the support poles to the work stand is not very secure and can be awkward and inconvenient. In addition, attachments using ropes or the like do not always yield satisfactory results. The vice-grip chain clamps are also not very secure as a means to attach accessories to the work stand. They can become dislodged, which is unsafe to the users of the work stand or those standing or working beneath it.